New and improved ways to treat hydrocephalus: Pursuit of a smart shunt

Abstract

The most common treatment for hydrocephalus is placement of a cerebrospinal fluid shunt to supplement or replace lost drainage capacity. Shunts are life-saving devices but are notorious for high failure rates, difficulty of diagnosing failure, and limited control options. Shunt designs have changed little since their introduction in 1950s, and the few changes introduced have had little to no impact on these long-standing problems. For decades, the community has envisioned a “smart shunt” that could provide advanced control, diagnostics, and communication based on implanted sensors, feedback control, and telemetry. The most emphasized contribution of smart shunts is the potential for advanced control algorithms, such as weaning from shunt dependency and personalized control. With sensor-based control comes the opportunity to provide data to the physician on patient condition and shunt function, perhaps even by a smart phone. An often ignored but highly valuable contribution would be designs that correct the high failure rates of existing shunts. Despite the long history and increasing development activity in the past decade, patients are yet to see a commercialized smart shunt. Most smart shunt development focuses on concepts or on isolated technical features, but successful smart shunt designs will be a balance between technical feasibility, economic viability, and acceptable regulatory risk. Here, we present the status of this effort and a framework for understanding the challenges and opportunities that will guide introduction of smart shunts into patient care.

An update on research priorities in hydrocephalus: overview of the third National Institutes of Health-sponsored symposium “Opportunities for Hydrocephalus Research: Pathways to Better Outcomes”

“…Despite many advances in the design of the CSF shunt, there have been few improvements in the rate of shunt malfunction, 75 with greater than 40% of first-time shunts failing within 2 years. 17,18,90,96,97,118 Shunt obstruction remains a critical challenge and represents the most common point of failure in patients with shunt-dependent hydrocephalus.…”

“…The common vision of a "smart" shunt includes incorporated sen-sors (flow or pressure), a pump or valve to regulate flow of CSF, installed electronics to drive a controlling algorithm, the ability to measure various parameters, two-way communication, and implanted power sources such as a battery. Described in concept and detail decades ago (reviewed by Lutz et al 75 ), the technological hurdles include low-power draw components, pressure sensors that are implantable with little to no drift, and importantly, appropriate algorithms for controlling such devices. Advanced models of CSF dynamics are needed to test smart shunts on the bench and in vitro.…”

Insinuating electronics in the brain

“…Whilst variable flow and variable pressure valves have been developed, there is a need for systems capable of delivering more advanced control, feedback, and communication. A ‘smart shunt’ of this sort has been envisaged for decades 25 . Reliable sensors in shunts could relay information about shunt functionality, CSF pressures, and the presence of infection.…”

Polyimide-based magnetic microactuators for biofouling removal

“…Unfortunately, there is no cure for this debilitating disease. The gold standard for treatment of hydrocephalus is the implantation of a shunt system to divert excess CSF from the brain to another part of the body [3]. However, shunt systems are notorious for their extremely high failure rate of more than 40% within 1 year and up to 85% within 10 years of implantation [4], [5].…”